Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

n-api: defer Buffer finalizer with SetImmediate #28082

Closed
wants to merge 2 commits into from
Closed

n-api: defer Buffer finalizer with SetImmediate #28082

wants to merge 2 commits into from

Commits on Jun 5, 2019

  1. src: fix off-by-one error in native SetImmediate 

    Previously, the throwing callback would have been re-executed in case
of an exception. This patch corrects the calculation to exclude the
callback.
    @addaleax
    addaleax committed Jun 5, 2019
    Configuration menu
    Copy the full SHA
    24a1905 View commit details
    Browse the repository at this point in the history

  2. n-api: defer Buffer finalizer with SetImmediate 

    We have a test that verifies that JS execution from the Buffer
finalizer is accepted, and that errors thrown are passed
down synchronously.

However, since the finalizer executes during GC, this is behaviour is
fundamentally invalid and, for good reasons, disallowed by the
JS engine. This leaves us with the options of either finding a way
to allow JS execution from the callback, or explicitly forbidding it on
the N-API side as well.

This commit implements the former option, since it is the more
backwards-compatible one, in the sense that the current situation
sometimes appears to work as well and we should not break that
behaviour if we don’t have to, but rather try to actually make it
work reliably.

Since GC timing is largely unobservable anyway, this commit moves
the callback into a `SetImmediate()`, as we do elsewhere in the code,
and a second pass callback is not an easily implemented option,
as the API is supposed to wrap around Node’s `Buffer` API.
In this case, exceptions are handled like other uncaught exceptions.

Two tests have to be adjusted to account for the timing difference.
This is unfortunate, but unavoidable if we want to conform to the
JS engine API contract and keep all tests.

Fixes: nodejs#26754
    @addaleax
    addaleax committed Jun 5, 2019
    Configuration menu
    Copy the full SHA
    26e2141 View commit details
    Browse the repository at this point in the history